Following distance The three-second rule
Stay at least three seconds behind the vehicle ahead. When it passes a fixed point, such as a sign, count three seconds. If you pass the same point before you finish counting, you are following too closely.
CVC 21703 · CA Driver's Handbook, "Tailgating (Following Too Closely)" and Glossary, "Three-second rule"What is the three-second rule in driving?
When the vehicle ahead passes a fixed point, such as a sign, count three seconds. If you pass that point before you finish counting, you are following too closely (Handbook).
Why this rule exists
A safe gap gives you the time to react when the driver ahead brakes hard or makes a mistake. Without it you hit them before your foot reaches the brake.
Step by step on the road
- Pick a sign or a post ahead.
- When the vehicle ahead passes it, count "one-thousand-one, one-thousand-two, one-thousand-three".
- If you reach the point before you finish, ease off the gas and let the gap grow; do not brake hard.
- Check again from time to time: the faster you go, the more feet three seconds covers.
- Keep the gap, so you have time to react if the driver ahead brakes hard or makes a mistake.
Common mistakes
- Judging the gap in car lengths instead of seconds.
- Keeping the same distance in feet at a higher speed.
- Braking hard to open the gap, which surprises the driver behind you.
On the DMV drive test
On business and residential streets the DL 32 sheet marks your spacing, and DL 955 wants you to keep a safe distance in front and to the sides. When you stop behind another car, you should be able to see its rear wheels: about half a car length back, with no excessive gap.
Based on the DMV’s Driving Test Criteria (DL 955) and its score sheet (DL 32). How the drive test works ›Questions people ask
Is the three-second rule the law in California?
The law gives no number: CVC 21703 says not to follow more closely than is reasonable and prudent, for the speed, the traffic and the road. The Handbook teaches the three-second rule to judge it.
Is the following distance two or three seconds in California?
The California Driver's Handbook uses three seconds. Count it from a fixed point, such as a sign.
How close can you stop behind another car?
Leave enough space to see its rear wheels (Handbook, "Braking"). The DMV drive test criteria put that at about half a car length.
Test yourself
Kees' three questions on this rule, the “Did you know?” facts and his tip come with the drive, in Voorrah! Pro.
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